Defects in sensory hair cells are thought to account for most forms of hereditary deafness. We aim to identify the components involved in hair-cell function by using a genetic approach. By screening over 7000 genomes (Tuebingen Screens I & II), we have identified a total of 24 genes that are required for balance and hearing in zebrafish. These circler mutants are analogous to the mouse shaker-waltzer mutants and can serve as alternative models for the study of human deafness. We are currently developing new ways of analyzing our mutants such stably expressing hair-cell specific markers, creating behavioral tests for auditory and vestibular function, and measuring physiological responses in hair cells and acousticolateralis nerves.